lipo's & spontoneous combustion

alrighty then! lets hear some stories and perhaps..............dare I request it, some good advice!!!

Best I heard lately was on RC Groups (I will find it and post a link) about someone receiving some lipo batts and as received, one of the cells in one of the lipos was starting to heat up while still in the unopened box! It did not go nuclear but, one of the cells lost voltage and the pack is not really usable any more!

How does he know it was overheating if the box was unopened The box may have been stored in a warm environment for a while.

Gord.

Ok Gord, I am stumped! I have been searching and just cannot find it. Details as I remember are, Lipo batteries (more than one pack) delived on a cold day, 2 degress C, packed in a cardboard box. Upon opening the box only one of the lipo packs was warm and it was around 40 degrees C (104 F). One cell measured 3.8x volts while the other or others were in the 3.9x volts range. The battery was monitored and over time the cell that measured 3.8x volts just kept dropping and dropping. No fire or explosion.

I've even tried hard to test how far before a lipo goes off in flames...

I've purposely whacked a lipo, dropped it till the corners are circles, hammered it, and even put a nail through it; and yet no fire.

the only time I was successful at causing some smoke was the nail through it, and overcharging till it ballooned and burst- but even then no fire.

Only time I was successful at actually seeing it burst into a fire was sticking the lipo in hot coal

Guys; pls do not attempt. This was my experiments seeing how far a Lipo can go before it burst into flames. As stated before none of the methods actually caused a fire other than throwing it in hot coals.

Nice video rcalldaylong!
I agree with you GB. I would add that excess heat is problem with lipo's and a properly manufactured lipo exposed to excessive heat may have a problem that will only show itself with use.

That might lead to the question of "How much checking do I need to do prior to trusting my new lipo?" Not to mention, how much equipment do I need to check my new lipo?

Having built and flown electric planes since the early 1990's, I still love what the lipo's enable my aircraft to do however, I try my best to determine the condition of my lipo's and any questionable ones are quickly disposed of.

Here are a few reports from guys who had unexplained fires.
There are more but this gives you an idea that "It can happen".

Quote:

"Had been (past tense) storing my lipos in a ceramic tub-no lid. Luckily I was home and went into "airplane" room and found one of the lipos was on fire, on the carpet, and was able to prevent damage or far worse. AND I WAS NOT CHARGING THEM. Since that incident, I store them in metal ammo box (drill 2 holes about 1/4 inch diameter for venting) and in lipo bags. Charging is in the lipo bag. To this day, do not know why the battery just went "crazy". Hope this incident may be helpful to someone: charge (don't leave room) and store in some type of fireproof container. bdel"https://www.rcgroups.com/forums/showt...e#post23648998

Quote:

"WOW had a call from my partner whiles at work about my opti power lipo blow up, and the thing is its wasn't even on charge so am a bit confuse to y this happen, I did notice that they were starting to puff and funny enough i did rang opti power yesterday regarding the battery puffing and they said to send them back and now this happen today, but the most thing I was happy about is that she was at home other wise I could have lost" http://www.rcheliaddict.co.uk/main-d...tml#post877508

Quote:

"A mate at our club this evening had a luck escape, a brand new Turnegy 5000 went up in his kitchen! no apperant reason (not on charge), he managed to get it out in time but i guess a bit of a freak out for his wife, little'un and himself. so remember lipos realy can burn the house down be carefull folks!"http://www.rcheliaddict.co.uk/main-d...tml#post831920

Quote:

"Bought a couple of ThunderPower G6 1800 3s's and ran one in my parkzone mustang today for about 5 minutes (timer )of balanced flying. Packed the plane up took the battery out and put it back into a zip lock bag... One of the cells exploded while carrying it back to the car? For a brand new pack that had been discharged and balanced im pretty amazed?"https://www.rcgroups.com/forums/showp...postcount=1136

Quote:

"Bro's just had a very close call, A brand new battery never crashed a 2S 480 mAh was just sitting there it was not used or charged on this day.. I was up stairs and heard a loud pop, I go down stairs only to find the lil' battery spewing grew smoke & spinning then it blew up ! Big flames. It almost cost me MY HOUSE, this darn lil' battery all by itself did this, I have learned my lesson all batteries are now stored on ammo cans, DO NOT STORE LIPOS, in the open !!!!!!!!!!!! Look what happened to me !!!!!!!!!!!!!!!!!!!! It managed to burn the wall, carpet,and tile.......Never again !!!!!!!!!!!!!!!"https://www.rcgroups.com/forums/showp...postcount=1098

Quote:

"After flying this morning I was doing some repairs and all of a sudden i heard a pop and smoke started pouring out of a Flightmax 3s 1300. I had not flown that pack. I just brought it home unflown. It was just sitting in the concrete block I store it in. I have a bucket of sand on hand that I dumped into the block and put its concrete top on. Smoked like crazy. Stunk up the cellar. There was another 1300 in the same block. The voltage on that measures fine but I don't know if the heat from the venting pack up against it might have damaged it? Now I am a little wary of my batteries. I treat them well. Have only charged them at 1C and do not abuse them. I recently balanced the pack. That was a small 1300. I recently got 6s 5000's".https://www.rcgroups.com/forums/showp...85&postcount=1